3-Pyridinesulfonic acid

In the era covered by "Tiangong Kaiwu", the main uses for showing alkali to it are as follows.
In the field of salt production, alkali is crucial. When boiling salt, there are many impurities in the brine, and the addition of alkali can promote the condensation and settlement of impurities and improve the purity of the salt. For example, in the process of sea salt boiling, by virtue of the action of alkali, impurities such as sediment and seaweed in the brine can be quickly precipitated. The salt thus produced is purer and whiter, of high quality, and more suitable for consumption and storage.
In the ceramic production industry, alkali also plays a key role. After the ceramic body is formed, it needs to be fired before the finished product can be obtained. Alkali can be used as a flux to reduce the melting point of ceramic raw materials, allowing ceramics to be sintered at relatively low temperatures, which not only saves fuel, but also improves the texture and color of ceramics. Like many ceramic kilns in Jingdezhen, when firing fine porcelain, an appropriate amount of alkali will be ingeniously added to make the surface of the porcelain as smooth as a mirror, and the glaze color is as warm as jade, which greatly enhances the beauty and quality of the porcelain.
The paper industry is also inseparable from alkali. When making paper from bamboo, bark, etc., the raw materials need to be soaked in lye and cooked. Alkali can accelerate the decomposition of raw material fibers, remove impurities such as lignin, and make the fibers easier to separate, resulting in uniform texture and good toughness paper. Many paper workshops in ancient times relied on this process to create paper products as famous as rice paper, laying the foundation for cultural inheritance.
In addition, in the printing and dyeing industry, alkali is used to adjust the pH of dye. Different dyes can be better colored and have better color fastness under specific pH environments. By adding alkali to adjust the pH value of dye, fabrics can be dyed evenly, with bright and lasting colors, which greatly enriches the color and pattern of fabrics and meets people's diverse needs for clothing and fabric decoration.

Acid is a common thing between heaven and earth, and its physical properties are unique, which is worth exploring.
Bearing the brunt, looking at its shape, under normal temperature, many acids are in the form of liquids, as smart as water. For example, common hydrochloric acid, clear and transparent, like a colorless elf, flows freely in the container, and is quite smart.
Furthermore, smell its smell, many acids emit a unique smell. The pungent smell of hydrochloric acid is like a sharp arrow, rushing straight into the nose, which instantly refreshes the mind; while acetic acid emits a unique sour fragrance, which can often be smelled in the kitchen, giving people a familiar feeling.
As for the boiling point of acid, it also varies. Sulfuric acid has a high boiling point and requires strong heat to boil. This property allows it to play a stable role in many industrial productions. In contrast, nitric acid has a relatively low boiling point and is volatile when heated slightly.
Solubility is also an important physical property of acids. Most acids can be miscible with water in any ratio, just like close friends. If sulfuric acid and water are miscible, a lot of heat will be released. This process needs to be handled with caution to prevent accidents.
In terms of density, different acids vary significantly. Sulfuric acid has a higher density than water. If it is slowly injected into water, it will sink to the bottom, like a stable stone.
In addition, the color of acid is not single. Most common acids are colorless, but there are exceptions. For example, concentrated nitric acid is slightly yellow due to the dissolution of nitrogen dioxide, just like the color of the setting sun, which adds a bit of unique charm.
To sum up, the physical properties of acids are rich and diverse, either related to form, or related to odor, boiling point, solubility, density, color, etc., which are all its unique signs. In the field of chemistry, it exudes fascinating light.

If you want to know whether the chemical properties of an acid are stable or not, you need to investigate its structure and reaction properties in detail. Acids can ionize hydrogen ions in water. Different acids have different degrees of chemical stability.
View strong acids such as sulfuric acid and hydrochloric acid are very acidic and very active under normal conditions. Sulfuric acid has strong oxidation, dehydration and water absorption. In many reactions, it can quickly react with metals, metal oxides, etc., which shows its chemical activity and poor stability. Hydrochloric acid is also highly acidic and can react with many substances, such as reacting with active metals to form hydrogen gas, which shows that it is easily changed in chemical reactions and has weak stability. < Br >
However, weak acids such as acetic acid have a small degree of ionization, and it is relatively difficult to release hydrogen ions. In normal environments, its reactivity is lower than that of strong acids, and its chemical properties are slightly stable. Another example is carbonic acid, which is easy to decompose into carbon dioxide and water at room temperature, indicating that its chemical properties are not stable and it is difficult to maintain its own structure for a long time.
There are also some organic acids, because their structures contain special functional groups, and their chemical properties are also different. Some organic acids are relatively stable and can be stored under certain conditions; while some are easy to participate in various chemical reactions due to the activity of functional groups.
As for the stability of the chemical properties of acids, it depends on many factors such as its own structure, the environment it is in, and the substances it reacts with. It cannot be generalized. It is necessary to study the reaction characteristics of specific acids under different conditions in order to understand the stability of their chemical properties.

If you want to make an acid agent, there are three methods. The first is the method of calcination, the second is the method of fermentation, and the third is the method of synthesis.
Let's talk about the method of calcination first. Take the acid-containing properties of stones, such as plaster, green alum, etc., and put them in a furnace and calcine them with fierce fire. The stone is calcined by fire, and its properties change, and the acid is precipitated. In the past, gypsum was calcined and ground into a fine powder. It can be used for medicinal purposes and can also be adjusted in the diet to increase the sour taste. This is the use of the heat of fire to separate the acid in the stone and obtain an acid-making agent.
The second time I talk about the method of fermentation. Choose grains and fruits, such as rice, wheat, grapes, etc. First soak it in water to moisturize it, and then place it in a warm place to ferment it. During the fermentation process, microorganisms breed and metabolize to form acids. If you make wine from glutinous rice, it will have a sour taste in the wine after a long time. There is also vinegar made from grapes, which is also made into acid by fermentation. This method uses the power of microorganisms to make the material naturally produce acid, which is a commonly used method for making acid.
Let's talk about the method of synthesis. Take alkali and acid substances and mix them in proportion to make them chemically react to form new acids. If lime and vinegar are combined, calcium acetate can be obtained, and then other treatments can be used to obtain acetic acid. This chemical change is used to synthesize acids artificially, and the method needs to clarify the properties and proportions of the substance to be successful.
The above three methods of acid production each have their own uses. Calcination method is mostly used for ore acid production; fermentation method is commonly used in food acid production; chemical synthesis method is often used for artificial synthesis of specific acids. Engineers, pharmaceuticals, and people can choose their method according to their needs.

Those who ask today, ask what the price of a certain acid is in the market. This acid has a wide range of uses and is needed in both work and agriculture, so its price varies from time to time and varies from place to place.
Looking at the market, its price often fluctuates. If it is about its approximate range, the price per catty is between a few dozen and a few dozen at ordinary times. In case of bad weather, lack of raw materials, or various changes, the price may also fluctuate sharply.
Sometimes raw materials are abundant and the supply is not at risk. Coupled with competition from the same industry, the price may tend to be low, and the price per catty may be as low as more than ten. In the event of a natural disaster, the raw materials are damaged, or the transportation is blocked, resulting in a shortage of supply in the market, the price will rise, and it will also be 30 to 40 yuan per catty.
And in different places, the price varies. In prosperous cities, merchants gather, the circulation of goods is convenient, and the price may be slightly flat; in remote areas, the transportation is difficult and the cost increases, and the price is often higher.
Basically speaking, this acid is in the market price, usually between ten and thirty to forty yuan per catty. However, the actual price still depends on the situation at the time. The market conditions are ever-changing, and it cannot be generalized.